Question

我的选择器有这个定义：

if(isset($_POST["check"]) && $_POST["way"] == 1){

在我看来，我这样设置：

this.StateField = new UIDropdown<string>()
            {
                BackgroundColor = CoreTheme.COLOR_DEFAULT_INPUT_FIELD_BACKGROUND,
                PlaceholderText = "State",
                Data = new string[] { "AL", "AK", "AZ", "AR", "CA", "CO", "CT", "DE", "DC", "FL", "GA", "HI", 
                    "ID", "IL", "IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA", "MI", "MN", "MS", "MO", "MT", 
                    "NE", "NV", "NH", "NJ", "NM", "NY", "NC", "ND", "OH", "OK", "OR", "PA", "RI", "SC", "SD", 
                    "TN", "TX", "UT", "VT", "VA", "WA", "WV", "WI", "WY" },
                TextColor = CoreTheme.COLOR_DEFAULT_INPUT_FIELD_FOREGROUND,
                PlaceholderTextColor = CoreTheme.COLOR_DEFAULT_PLACEHOLDER_TEXT
            };

但是，未设置占位符值，而是将数组中的第一个元素显示为占位符值。如何为选择器显示占位符值？

我试图在Xamarin.Forms中尝试这样做，特别是对于Android。

Answer 1

我不相信UIPicker有一个占位符文字字段，所以

List<Model_State> states = new List<Model_State>();

Model_State unselected = new Model_State();
unselected.id = Enum_State.Unselected;
unselected.name = "Select State";

states.add(unselected);

Model_State AL = new Model_State();
AL.id = Enum_State.Alabama;
AL.name = "Alabama";

states.add(AL)

....再添加49个州

如何为我的选择器设置占位符值？

1 个答案: